1. Field of the Invention
The present invention relates to a holder for retaining a material, such as a wafer, to be processed (hereinafter referred to as “workpiece holder” or a “susceptor”), in a processing apparatus such as a semiconductor manufacturing apparatuses, and a processing apparatus using the same. In particular, the present invention relates to a workpiece holder having superior reliability against heat cycle, and to a processing apparatus having such workpiece holder.
2. Description of the Related Art
Heretofore, in manufacturing steps of semiconductor devices, film-formation or etching treatment have been performed on workpiece, that is, semiconductor substrates. A processing apparatus for processing such substrates is provided with a susceptor, which is a holder for retaining a semiconductor substrate during its treatment.
A conventional susceptor described above has been disclosed in, for example, Japanese Unexamined Patent Application Publication No. 7-153706.
However, the conventional susceptor described above has such problems as described below. That is, in order to supply an inert gas inside a supporting table, a gas supply tube must be provided for the susceptor, and in addition, devices necessary for supplying an inert gas, such as mass flow controller, must be connected to the gas supply tube. Consequently, the structure of the susceptor becomes complicated, and as a result, manufacturing cost of the susceptor used as a workpiece holder is increased.
In addition, when this susceptor is used, running cost of the susceptor is also increased since an inert gas must always be supplied inside the supporting table.